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  Subjects -> VETERINARY SCIENCE (Total: 194 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 1)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 6)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 7)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 10)
American Journal of Primatology     Hybrid Journal   (Followers: 7)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 17)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 2)
Animal Behaviour     Hybrid Journal   (Followers: 134)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5)
Animal Health Research Reviews     Hybrid Journal   (Followers: 4)
Animal Nutrition     Open Access   (Followers: 4)
Animal Reproduction Science     Hybrid Journal   (Followers: 6)
Animals     Open Access   (Followers: 6)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 8)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 6)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 2)
Australian Veterinary Journal     Hybrid Journal   (Followers: 10)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 5)
Avian Diseases Digest     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 3)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 1)
Bangladesh Veterinarian     Open Access   (Followers: 1)
BMC Veterinary Research     Open Access   (Followers: 5)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Bulletin of Animal Health and Production in Africa     Full-text available via subscription   (Followers: 1)
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 7)
Case Reports in Veterinary Medicine     Open Access   (Followers: 4)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access  
Companion Animal     Full-text available via subscription   (Followers: 5)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 2)
Equine Health     Full-text available via subscription   (Followers: 1)
Equine Veterinary Education     Hybrid Journal   (Followers: 8)
Equine Veterinary Journal     Hybrid Journal   (Followers: 11)
Ethiopian Veterinary Journal     Open Access   (Followers: 4)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Frontiers in Veterinary Science     Open Access  
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 6)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 3)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 2)
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 3)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
InVet     Open Access  
Iranian Journal of Applied Animal Science     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 2)
Journal of Veterinary Science & Technology     Open Access   (Followers: 3)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 6)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 2)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 5)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 10)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 4)
Journal of Experimental and Applied Animal Sciences     Open Access  
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 5)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 3)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 9)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 24)
Journal of the Hellenic Veterinary Medical Society     Full-text available via subscription   (Followers: 2)
Journal of the Selva Andina Research Society     Open Access  
Journal of the South African Veterinary Association     Open Access   (Followers: 1)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 4)
Journal of Veterinary Advances     Open Access   (Followers: 3)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 3)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 4)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 7)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 12)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 14)
Journal of Veterinary Medical Education     Partially Free   (Followers: 11)
Journal of Veterinary Medicine     Open Access   (Followers: 4)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 2)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 5)
Journal of Veterinary Science & Medical Diagnosis     Hybrid Journal   (Followers: 1)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 1)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 5)
Kenya Veterinarian     Full-text available via subscription   (Followers: 3)

        1 2     

Journal Cover   Veterinary Microbiology
  [SJR: 1.425]   [H-I: 84]   [8 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
   Published by Elsevier Homepage  [2800 journals]
  • High frequency of virulence genes among Escherichia coli with the blaCTX-M
           genotype from diarrheic piglets in China
    • Abstract: Publication date: Available online 29 August 2015
      Source:Veterinary Microbiology
      Author(s): Wen-Hui Zhang, Si-Qi Ren, Xi-Xi Gu, Wan Li, Ling Yang, Zhen-Ling Zeng, Ya-Hong Liu, Hong-Xia Jiang
      The purpose of this study was to characterize the virulence potential and determine the molecular epidemiology of extended-spectrum β-lactamases (ESBLs) in CTX-M-producing Escherichia coli isolated from piglets with diarrhea in China. A total of 62 E. coli isolates were obtained among which 49 and 13 were collected from diarrheic and healthy piglets, respectively. Cefotaxime resistant strains were screened for the presence of ESBL, adhesin and exotoxin genes as well as for their biofilm-forming ability. Characterization of bla CTX-M plasmids was determined by conjugation along with the determination of genetic relatedness and plasmid replicon type. CTX-M producers were found in 36 isolates with 6 different subtypes: bla CTX-M-14,27,65 from CTX-M-9G (n=27) and bla CTX-M-55,15,79 from CTX-M-1G (n=22). This also included 13 isolates that carried two different CTX-M genes. Thirty of 36CTX-M producers and 12 of 13 multiple CTX-M alleles were confirmed from diarrheic piglets. The presence of the iron regulatory gene irp2 as well as EAST1 was found in 83.3% (25/30) of CTX-M-producing isolates from diarrheic piglets and these were significantly better biofilm formers. PFGE profiles of CTX-M-positive isolates indicated the spread of multidrug resistance was primarily horizontal and spread via transferable plasmids. Most bla CTX-M-9G genes (10/17) were located on the IncFIB type plasmid with sizes of 40-145kb, while the bla CTX-M-1G (11/16) genes were located on the ∼100kb IncN-type plasmid. Together, our findings demonstrate that CTX-M ESBL-producing E.coli from diarrheic piglets were associated with serious multidrug resistance, increased biofilm-forming ability and the irp2 gene of HPI. Our findings highlight the need to urgent control the spread of resistant strains through food chain.


      PubDate: 2015-08-29T19:23:01Z
       
  • Antimicrobial susceptibility patterns of clinical Escherichia coli
           isolates from dogs and cats in the United States: January 2008 through
           January 2013
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Kamoltip Thungrat, Stuart B. Price, D. Mark Carpenter, Dawn Merton Boothe
      Escherichia coli is among the most common bacterial pathogens in dogs and cats. The lack of a national monitoring program limits evidence-based empirical antimicrobial choices in the United States. This study describes antimicrobial susceptibility patterns for presumed clinical E. coli isolates from dogs (n =2392) or cats (n =780) collected from six geographic regions in the United States between May 2008 and January 2013. Minimum inhibitory concentrations (MIC) were determined for 17 drugs representing 6 drug classes. Urinary tract isolates were most common (71%). Population MIC distributions were generally bimodal with the second mode above the resistant breakpoint for all drugs except gentamicin, amikacin, and meropenem. The MIC90 exceeded the susceptible breakpoint for ampicillin, amoxicillin–clavulanic acid, cephalothin (surrogate drug for cephalexin), and doxycycline but was below the susceptible breakpoint for all others. None of isolates was susceptible or resistant to all drug tested; 46% were resistant to 1 or 2 antimicrobial categories, and 52% to more than three categories. The resistance percentages were as follows: doxycycline (100%), cephalothin (98%)>ampicillin (48%)>amoxicillin–clavulanic acid (40%)>ticarcillin–clavulanic acid (18%)>cefpodoxime (13%), cefotaxime (12%), cefoxitin (11%), cefazolin (11%), enrofloxacin (10%), chloramphenicol (9.6%)>ciprofloxacin (9.2%), ceftazidime (8.7%), trimethoprim–sulfamethoxazole (7.9%), gentamicin (7.9%)>meropenem (1.5%), amikacin (0.7%) (P <0.05). Resistance to ampicillin and amoxicillin–clavulanic acid was greatest in the South-Central region (P <0.05). E. coli resistance may preclude empirical treatment with doxycycline, cephalexin, ampicillin, or amoxicillin–clavulanic acid. Based on susceptibility patterns, trimethoprim–sulfonamides may be the preferred empirical oral treatment.


      PubDate: 2015-08-07T20:23:24Z
       
  • Evidence of possible vertical transmission of Tembusu virus in ducks
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Ying Zhang, Xiuli Li, Hao Chen, Jinfeng Ti, Guoping Yang, Lu Zhang, Yunjian Lu, Youxiang Diao
      In 2013, Tembusu virus (TMUV) infection was successively observed on several breeding duck farms in Shandong province, China. Affected ducks showed consistently acute anorexia, diarrhea and egg production drop. 125 hatching eggs produced by TMUV infected breeding ducks from four duck farms were collected. Among them, 35 hatching eggs were selected randomly from all before incubation for vitelline membrane samples collection. The rest of 90 hatching eggs were incubated routinely. As a result, 16 hatching eggs were found non-embryonated, 28 duck embryos died during incubation and 46 newly hatched ducklings were obtained. Vitelline membranes of non-embryonated hatching eggs, vitelline membrane, brain or liver samples of dead embryos and brain samples of newly hatched ducklings were collected for virus detection. Samples collected from one egg, embryo or duckling were treated as one. Consequently, 18 of 35 (51.43%) hatching eggs, 2 of 16 (12.50%) non-embryonated duck eggs, 17 of 28 (60.71%) dead duck embryos and 5 of 46 (10.87%) newly hatched ducklings were detected positive for TMUV using NS3-based RT-PCR. Overall, 42 of 125 (33.6%) eggs were positive for TMUV. A virus strain, designated as TMUV-SDDE, was isolated from one of these dead duck embryos which were detected TMUV positive. The results of phylogenetic analysis showed that E gene of TMUV-SDDE virus was closely related to other TMUV strains isolated in China during 2010–2013. Pathogenicity studies showed that TMUV-SDDE strain was virulent to ducklings. This is the first report that TMUV is isolated from duck embryos. The findings provide evidence of possible vertical transmission of TMUV from breeding ducks to ducklings.


      PubDate: 2015-08-07T20:23:24Z
       
  • Modes of transmission of Simian T-lymphotropic Virus Type 1 in
           semi-captive mandrills (Mandrillus sphinx)
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Marion Roussel, Dominique Pontier, Barthélémy Ngoubangoye, Mirdad Kazanji, Delphine Verrier, David Fouchet
      Non-human primates (NHPs) often live in inaccessible areas, have cryptic behaviors, and are difficult to follow in the wild. Here, we present a study on the spread of the simian T-lymphotropic Virus Type 1 (STLV-1), the simian counterpart of the human T-lymphotropic virus type 1 (HTLV-1) in a semi-captive mandrill colony. This study combines 28 years of longitudinal monitoring, including behavioral data, with a dynamic mathematical model and Bayesian inference. Three transmission modes were suspected: aggressive, sexual and familial. Our results show that among males, STLV-1 transmission occurs preferentially via aggression. Because of their impressive aggressive behavior male mandrills can easily transmit the virus during fights. On the contrary, sexual activity seems to have little effect. Thus transmission appears to occur primarily via male–male and female–female contact. In addition, for young mandrills, familial transmission appears to play an important role in virus spread.


      PubDate: 2015-08-07T20:23:24Z
       
  • Viral load of equine herpesviruses 2 and 5 in nasal swabs of actively
           racing Standardbred trotters: Temporal relationship of shedding to
           clinical findings and poor performance
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Helena Back, Karin Ullman, Louise Treiberg Berndtsson, Miia Riihimäki, Johanna Penell, Karl Ståhl, Jean-François Valarcher, John Pringle
      The equine gamma herpesviruses 2 and 5 (EHV-2 and -5) have frequently been observed in the equine population and until recently presumed low to nonpathogenic. However, recent reports linking presence of equine gamma herpesviruses with clinical signs of mild to severe lung disease, suggest that the role of these viruses in respiratory disease and poor performance syndrome is still unclear. Moreover, baseline data regarding the temporal pattern of shedding of EHV-2 and EHV-5 within stables and within individual actively racing horses have been lacking. In a prospective longitudinal study, we followed elite racing Standardbred trotters at monthly intervals for 13 months, to investigate whether the amount of EHV-2 and EHV-5 shedded in nasal secretions varied over time within and between individual horses. Sixty-six elite horses were investigated by analyzing nasal swabs and serum samples, a health check and evaluation of athletic performance monthly during the study period. Nasal swabs were analyzed with two newly developed qPCR assays for EHV-2 and EHV-5, respectively. Of 663 samples, 197 (30%) were positive for EHV-2 and 492 (74%) positive for EHV-5. Furthermore, 176 (27%) of the samples were positive for both EHV-2 and EHV-5 simultaneously. There was considerable variation in the amount and frequency of shedding of EHV-2 and EHV-5 within and between individual horses. Viral load varied seasonally, but neither EHV-2 nor EHV-5 viral peaks were associated with clinical respiratory disease and/or poor performance in racing Standardbred trotters.


      PubDate: 2015-08-07T20:23:24Z
       
  • Sub-inhibitory concentrations of penicillin G induce biofilm formation by
           field isolates of Actinobacillus pleuropneumoniae
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): S. Hathroubi, S.-È. Fontaine-Gosselin, Y.D.N. Tremblay, J. Labrie, M. Jacques
      Actinobacillus pleuropneumoniae is a Gram-negative bacterium and causative agent of porcine pleuropneumonia. This is a highly contagious disease that causes important economic losses to the swine industry worldwide. Penicillins are extensively used in swine production and these antibiotics are associated with high systemic clearance and low oral bioavailability. This may expose A. pleuropneumoniae to sub-inhibitory concentrations of penicillin G when the antibiotic is administered orally. Our goal was to evaluate the effect of sub-minimum inhibitory concentration (MIC) of penicillin G on the biofilm formation of A. pleuropneumoniae. Biofilm production of 13 field isolates from serotypes 1, 5a, 7 and 15 was tested in the presence of sub-MIC of penicillin G using a polystyrene microtiter plate assay. Using microscopy techniques and enzymatic digestion, biofilm architecture and composition were also characterized after exposure to sub-MIC of penicillin G. Sub-MIC of penicillin G significantly induced biofilm formation of nine isolates. The penicillin G-induced biofilms contained more poly-N-acetyl-d-glucosamine (PGA), extracellular DNA and proteins when compared to control biofilms grown without penicillin G. Additionally, penicillin G-induced biofilms were sensitive to DNase which was not observed with the untreated controls. Furthermore, sub-MIC of penicillin G up-regulated the expression of pgaA, which encodes a protein involved in PGA synthesis, and the genes encoding the envelope-stress sensing two-component regulatory system CpxRA. In conclusion, sub-MICs of penicillin G significantly induce biofilm formation and this is likely the result of a cell envelope stress sensed by the CpxRA system resulting in an increased production of PGA and other matrix components.


      PubDate: 2015-08-07T20:23:24Z
       
  • Effects of porcine epidemic diarrhea virus on porcine monocyte-derived
           dendritic cells and intestinal dendritic cells
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Qi Gao, Shanshan Zhao, Tao Qin, Yinyan Yin, Qian Yang
      Infection with porcine epidemic diarrhea virus (PEDV) causes damage to intestinal epithelial cells and results in acute diarrhea and dehydration with high mortality rates in swine. Dendritic cells (DCs) are highly effective antigen-presenting cells widely distributed beneath the intestinal epithelium, thus making them an early target for virus contact. DCs uptake and present viral antigens to T cells, which then initiate a distinct immune response. In this study, we investigated how attenuated PEDV (CV777) affects the function of porcine monocyte-derived dendritic cells (Mo-DCs). Our results show that the expression of Mo-DC surface markers such as SWC3a+CD1a+, SWC3a+CD80/86+ and SWC3a+SLA-II-DR+ is increased after infection with CV777 for 24h. Mo-DCs infected with CV777 produce higher levels of IL-12 and INF-γ compared to mock-infected Mo-DCs but the expression profile for IL-10 does not change. Interactions between Mo-DCs and CV777 significantly influence the stimulation of the T cell response in vitro. Consistent with these results, after 48h of CV777 infection, there is enhancement in the ability of porcine intestinal DCs to sample the antigen and activate T-cell proliferation in vivo. The enhancement of sampling and presentation is most pronounced for immature Mo-DCs. These results suggest that CV777 stimulates the ability of Mo-DCs to sample and present antigen. We conclude that CV777 may be a useful vaccine to trigger adaptive immunity.


      PubDate: 2015-08-07T20:23:24Z
       
  • Isolation and identification of Vibrio toranzoniae associated with
           diseased red conger eel (Genypterus chilensis) farmed in Chile
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Aide Lasa, Ruben Avendaño-Herrera, Juan M. Estrada, Jesús L. Romalde
      The present study deals with the first isolation of Vibrio toranzoniae from cultured red conger eel (Genypterus chilensis). During the summer season of 2011, mortalities were observed in young red conger eel at one aquaculture experimental rearing system in Quintay, Valparaiso, Chile. The microbiological analysis of the diseased fish resulted in the isolation of three dominant and representative isolates, designated as R.17, R.18 and R.19, which were obtained from gill, fin and external lesions from three different fish, respectively. All isolates were identified as V. toranzoniae by means of a polyphasic taxonomic approach, including phenotypic characterization, sequencing of 16S rRNA and housekeeping genes, and DNA–DNA hybridization. Inoculation of a representative strain (R18) in turbot as model fish species demonstrated the pathogenic potential for fish of the Chilean isolates. Results obtained indicate that the geographical and host distribution of V. toranzoniae is wider than expected, and that this species may have negative incidence in the culture of marine organisms.


      PubDate: 2015-08-07T20:23:24Z
       
  • Role of Streptococcus uberis adhesion molecule in the pathogenesis of
           Streptococcus uberis mastitis
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Raúl A. Almeida, Oudessa Kerro Dego, Susan I. Headrick, Mark J. Lewis, Stephen P. Oliver
      Adherence to and internalization into mammary epithelial cells are central mechanisms in the pathogenesis of S. uberis mastitis. Through these pathogenic strategies, S. uberis reaches an intracellular environment where humoral host defenses and antimicrobials in milk are essentially ineffective, thus allowing persistence of this pathogen in the mammary gland. We reported that S. uberis expresses a surface adhesion molecule (SUAM) that has affinity for lactoferrin (LF) and a central role adherence to and internalization of S. uberis into bovine mammary epithelial cells. To define the role of SUAM in the pathogenesis of S. uberis mastitis, we created a sua gene deletion mutant clone of S. uberis UT888 (Δsua S. uberis UT888) unable to express SUAM. When tested in vitro, Δsua S. uberis UT888 was defective in adherence to and internalization into bovine mammary epithelial cells. To prove that the absence of SUAM reduces bacterial attachment, subsequent colonization and infection of bovine mammary glands, the wild type S. uberis UT888 and its isogenic Δsua S. uberis UT888 were infused into mammary quarters of dairy cows. Results showed that fewer mammary glands infused with Δsua S. uberis UT888 become infected than those infused with the isogenic parental strain. Furthermore, mammary glands infused with Δsua S. uberis UT888 had less severe clinical symptoms as compared to those infused with the isogenic parental strain. These results suggest that the SUAM mutant clone was less virulent than the isogenic parental strain which further substantiates the role of SUAM in the pathogenesis of S. uberis mastitis.


      PubDate: 2015-08-07T20:23:24Z
       
  • The immune response of bovine mammary epithelial cells to live or
           heat-inactivated Mycoplasma bovis
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Christina Zbinden, Paola Pilo, Joachim Frey, Rupert M Bruckmaier, Olga Wellnitz
      Mycoplasma bovis is an emerging bacterial agent causing bovine mastitis. Although these cell wall-free bacteria lack classical virulence factors, they are able to activate the immune system of the host. However, effects on the bovine mammary immune system are not yet well characterized and detailed knowledge would improve the prevention and therapy of mycoplasmal mastitis. The aim of this study was to investigate the immunogenic effects of M. bovis on the mammary gland in an established primary bovine mammary epithelial cell (bMEC) culture system. Primary bMEC of four different cows were challenged with live and heat-inactivated M. bovis strain JF4278 isolated from acute bovine mastitis, as well as with the type strain PG45. The immune response was evaluated 6 and 24h after mycoplasmal challenge by measuring the relative mRNA expression of selected immune factors by quantitative PCR. M. bovis triggered an immune response in bMEC, reflected by the upregulation of tumor necrosis factor-α, interleukin(IL)-1β, IL-6, IL-8, lactoferrin, Toll-like receptor-2, RANTES, and serum amyloid A mRNA. Interestingly, this cellular reaction was only observed in response to live, but not to heat-inactivated M. bovis, in contrast to other bacterial pathogens of mastitis such as Staphylococcus aureus. This study provides evidence that bMEC exhibit a strong inflammatory reaction in response to live M. bovis. The lack of a cellular response to heat-inactivated M. bovis supports the current hypothesis that mycoplasmas activate the immune system through secreted secondary metabolites.


      PubDate: 2015-08-07T20:23:24Z
       
  • Genotyping and determining the distribution of prevalent G and P types of
           group A bovine rotaviruses between 2010 and 2012 in Iran
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Omid Madadgar, Ahmad Nazaktabar, Hadi Keivanfar, Taghi Zahraei Salehi, Samad Lotfollah Zadeh
      Determination and distribution of the G and P genotypes of group A bovine rotavirus was investigated on 386 fecal samples collected from calves with diarrhea using a semi-nested RT-PCR typing assay. Samples were collected from 11 provinces of Iran during 2010–2012. The provinces divided into 5 different groups based on geographical distance and climates. One hundred and nine samples (28.2%) were confirmed positive for rotavirus group A using ELISA. 75 positive samples were selected randomly and subjected to typing assay. G10 (50.6%) and P[11] (64%) were detected more than G6 (21.3%) and P[5] (9.3%). No any G8 and P[1] were observed. Of the 75 samples analyzed by RT-PCR in each geographical areas named as the south of Alborz mountain ranges area, the north-east area, the central area, the north-west area and the south-east area, number of samples with G10 genotype were 19, 9, 9, 0 and 1; G6 were 8, 0, 3, 5 and 0; P[11] were 25, 7, 11, 5 and 0 and finally P[5] were 5, 0, 2, 0 and 0 in each area, respectively. The most common VP7/VP4 combinations were G10P[11] (40%), G6P[11] (12%), G6P[5] (5.3%) and G10P[5] (2.6%). Phylogenetic analysis of one strain showed high identity with strain B223. Since the identification of G and P genotypes and their diversity is fundamental to development and use of effective vaccines, we determined the most prevalence G and P genotypes of bovine rotavirus group A (BRVA) in a broad area of Iran.


      PubDate: 2015-08-07T20:23:24Z
       
  • Propagation of the Israeli vaccine strain of Anaplasma centrale in tick
           cell lines
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Lesley Bell-Sakyi, Ana M. Palomar, Emma L. Bradford, Varda Shkap
      Anaplasma centrale has been used in cattle as a live blood vaccine against the more pathogenic Anaplasma marginale for over 100 years. While A. marginale can be propagated in vitro in tick cell lines, facilitating studies on antigen production, immunisation and vector-pathogen interaction, to date there has been no in vitro culture system for A. centrale. In the present study, 25 cell lines derived from 13 ixodid tick species were inoculated with the Israeli vaccine strain of A. centrale and monitored for at least 12 weeks by microscopic examination of Giemsa-stained cytocentrifuge smears. Infection of 19 tick cell lines was subsequently attempted by transfer of cell-free supernate from vaccine-inoculated tick cells. In two separate experiments, rickettsial inclusions were detected in cultures of the Rhipicephalus appendiculatus cell line RAE25 28–32 days following inoculation with the vaccine. Presence of A. centrale in the RAE25 cells was confirmed by PCR assays targeting the 16S rRNA, groEL and msp4 genes; sequenced PCR products were 100% identical to published sequences of the respective genes in the Israeli vaccine strain of A. centrale. A. centrale was taken through three subcultures in RAE25 cells over a 30 week period. In a single experiment, the Dermacentor variabilis cell line DVE1 was also detectably infected with A. centrale 11 weeks after inoculation with the vaccine. Availability of an in vitro culture system for A. centrale in tick cells opens up the possibility of generating a safer and more ethical vaccine for bovine anaplasmosis.


      PubDate: 2015-08-07T20:23:24Z
       
  • Isolation of a novel thermophilic Campylobacter from cases of spotty liver
           disease in laying hens and experimental reproduction of infection and
           microscopic pathology
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Tim R. Crawshaw, Jeremy I. Chanter, Stuart C.L. Young, Shaun Cawthraw, Adrian M. Whatmore, Mark S. Koylass, Ana B. Vidal, Francisco J. Salguero, Richard M Irvine
      The condition known as spotty liver disease or spotty liver syndrome can cause significant mortality in free range laying hen flocks. It has been described in Europe and Australia but the aetiology has not been established. There are similarities between spotty liver disease and avian vibrionic hepatitis, a condition which was reported in the 1950s. A Vibrio-like organism was suspected to be the cause of avian vibrionic hepatitis, although this organism was never fully characterised. We report the isolation of a novel Campylobacter from five separate outbreaks of spotty liver disease. The conditions required for culture, the growth characteristics, electron microscopical morphology and results of the phenotypic tests used in the identification of this novel Campylobacter sp. are described. The novel Campylobacter is slow growing and fastidious and does not grow on media routinely used for isolating Campylobacter sp. The morphology is typical for a Campylobacter sp. and phenotypic tests and a duplex real time PCR test differentiate the novel Campylobacter from other members of the genus. 16S rRNA analysis of 19 isolates showed an identical sequence which appears to represent a hitherto unknown sub lineage within the genus Campylobacter. Experimental intraperitoneal infection of four week old SPF chickens produced microscopic liver pathology indistinguishable from natural disease and the novel Campylobacter was recovered from the experimentally infected chicks. The isolates described appear to be a possible causal organism for spotty liver disease.


      PubDate: 2015-08-07T20:23:24Z
       
  • First molecular survey of Anaplasma bovis in small ruminants from Tunisia
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Mourad Ben Said, Hanène Belkahia, Maroua Karaoud, Maha Bousrih, Mouna Yahiaoui, Monia Daaloul-Jedidi, Lilia Messadi
      To date, no information is available regarding the presence of Anaplasma bovis in the South Mediterranean area. In this study, prevalence, risk factors, and genetic diversity of A. bovis were assessed in small ruminants. A total of 563 healthy small ruminants (260 sheep and 303 goats), from 25 randomly selected flocks located in 5 localities from two bioclimatic areas in Tunisia, were investigated for the detection of A. bovis in blood by nested polymerase chain reaction (nPCR) assay. The overall infection rates of A. bovis were 42.7 and 23.8% in sheep and goats, respectively. Goats located in a sub-humid area were statistically more infected than those located in a humid area. A. bovis prevalence rate varied significantly according to sheep and goat flocks, and to the sheep breed. Infection with A. bovis was validated by sequencing. Sequence analysis based on the 16S rRNA gene showed that A. bovis from Tunisian goats and sheep clustered with other strain sequences detected from wild and domestic animals and published in GenBank. This study gives the first insight of presence of A. bovis DNA in small ruminants in Tunisia and suggests that these animal species may be playing an important role in the bovine anaplasmosis natural cycle caused by A. bovis in the South Mediterranean ecosystem.


      PubDate: 2015-08-07T20:23:24Z
       
  • Genetic characteristics of canine bocaviruses in Korean dogs
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Jeong-Won Choi, Kyung-Hyun Lee, Jae-Il Lee, Myoung-Heon Lee, Kyoung-Ki Lee, Jae-Ku Oem
      To survey for canine bocavirus (CBoV) infection, 83 Korean dogs showing several clinical signs were collected in different provinces from January 2013 to July 2014. Using polymerase chain reaction (PCR) and in situ hybridization, CBoVs were detected in intestine and/or lung samples of 8 dogs (9.6%). To reveal the genetic characteristics of CBoVs, partial or complete regions of CBoVs were sequenced. In phylogenetic trees, 8 CBoVs fell into three clusters. The CBoV strains 13D226-1, 13D250, and 14Q216 were closely related to the CBoV HK831F strain, and the CBoV 14D142 strain was related to the CBoV HK882F strain. Lastly, CBoV 13D003, 13D095, 14D193, and 14Q209 strains were related to CBoV Dis-023, Dis-040, and Dis-046 strains. Interestingly, no canine pathogens were found in dogs in which four CBoVs (13D003, 13D0095, 14D142, and 14D193 strains) were detected and three of them (13D003, 13D095, and 14D193 strains) had a unique deletion (18 nucleotides) in the VP2 gene. Further, the open reading frame 4 (ORF4) region was absent in these 4CBoVs, but found in the other strains, which indicates that the absence of the ORF4 region rather than a unique deletion may have an influence on the pathogenesis of CBoV in dogs.


      PubDate: 2015-08-07T20:23:24Z
       
  • Detection of rotavirus species A, B and C in domestic mammalian animals
           with diarrhoea and genotyping of bovine species A rotavirus strains
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Peter H. Otto, Stefanie Rosenhain, Mandy C. Elschner, Helmut Hotzel, Patrycja Machnowska, Eva Trojnar, Kathrin Hoffmann, Reimar Johne
      Rotaviruses (RVs) are a major cause of neonatal diarrhoea in humans and animals worldwide. In this study, 425 faecal samples were collected between 1999 and 2013 from diarrhoeic livestock and companion animals at different locations in Germany and tested for RVs. A previously published real-time RT-PCR assay was optimized for detection of a larger variety of RV species A (RVA) strains, and real-time RT-PCR assays for detection of RV species B (RVB) and C (RVC) were newly developed. The detection limits of the assays were 1.54×102, 3.95×102 and 3.60×103 genome copies for RVA, RVB and RVC, respectively. RVA was identified in 85.2% of bovine samples, 51.2% of porcine samples, 50.0% of feline samples, 43.2% of equine samples and 39.7% of canine samples. RVB was found in 3.0% of bovine samples, 2.7% of equine samples and 1.6% of porcine samples. RVC was detected in 31.0% of porcine samples, 21.7% of feline samples, 9.0% of canine samples and 6.0% of bovine samples. For genotyping, 101 RVA-positive bovine samples were further analysed by semi-nested RT-PCR. Genotype combination G6P[5] was most frequently detected (67.3% of samples), followed by G6P[11] (13.9%), G10P[5] (4.0%), G8P[11] (3.0%), G6P[1] (1.0%), and G10P[11] (1.0%). Mixed RVA infections were detected in 5.9% of samples; no or incomplete typing was possible in 4.0% of the samples. This first overview on RV species and RVA genotypes in diarrhoeic livestock and companion animals from Germany indicates a broad circulation of a large variety of RVs.


      PubDate: 2015-08-07T20:23:24Z
       
  • Influence of temperature on Betanodavirus infection in Senegalese sole
           (Solea senegalensis)
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Sandra Souto, Jose G. Olveira, Isabel Bandín
      In this study Senegalese sole juveniles were experimentally infected with a reassortant Betanodavirus strain at three different temperatures: 22°C, 18°C and 16°C by bath challenge and cohabitation. The results obtained showed that virus virulence decreased by reducing the water temperature. At 22°C mortalities reached 100%, at 18°C they ranged from 75 to 80% and at 16°C only 8% of the fish died. In addition, horizontal transmission was demonstrated regardless of the rearing temperature. At 16°C active viral replication was detected up to 66 days post-infection, but no signs of the disease were observed and only a very low level of mortality was recorded. The increase in water temperature from 16 to 22°C caused a quick rise in the viral load and a subsequent outbreak of mortalities. These findings demonstrate that this reassortant Betanodavirus strain can cause a persistent infection in Senegalese sole at low temperatures (16°C) for long periods of time, and when temperature increases the virus is able to trigger an acute infection and provoke high mortalities.


      PubDate: 2015-08-07T20:23:24Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4




      PubDate: 2015-08-07T20:23:24Z
       
  • Characterization of three porcine reproductive and respiratory syndrome
           virus isolates from a single swine farm bearing strong homology to a
           vaccine strain
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Yi-feng Jiang, Tian-qi Xia, Yan-jun Zhou, Ling-xue Yu, Shen Yang, Qin-feng Huang, Li-wei Li, Fei Gao, Ze-hui Qu, Wu Tong, Guang-zhi Tong
      Three porcine reproductive and respiratory syndrome viruses (PRRSV), NT1, NT2, and NT3, were isolated from three dying piglets from a single pig farm in Jiangsu Province, China. Whole genome sequencing revealed that the three isolates share the highest homology with JXA1-P80, an attenuated vaccine strain developed by serial passage of highly pathogenic PRRSV JXA1 in MARC-145 cells. More than ten amino acids residues in ORF1a, ORF1b, GP4, and GP5 that were thought to be unique to JXA1 attenuated on MARC-145 cells were each found in the corresponding locations of NT1, NT2, and NT3. In virulence assays, piglets infected with NT1, NT2, or NT3 exhibited clinical signs of disease, including high fever, anorexia, and respiratory distress, leading to the death of the majority of the piglets within two weeks. Collectively, these data indicate that NT1, NT2, and NT3 are highly pathogenic PRRSVs and they are likely to be revertants of the vaccine strain JXA1-P80.
      Graphical abstract image

      PubDate: 2015-08-07T20:23:24Z
       
  • Presence of leptospires on genital tract of mares with reproductive
           problems
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Camila Hamond, Cristiane P. Pestana, Cláudio Marcos Rocha-de-Souza, Luis Eduardo R. Cunha, Felipe Z. Brandão, Marco Alberto Medeiros, Walter Lilenbaum
      Leptospirosis is a zoonotic disease of global importance, and has a worldwide distribution. Equine leptospirosis is commonly manifested by recurrent uveitis, reproductive disorders, as abortions, embryonic absorption, stillbirth and the birth of weak foals. The aim of this study was to verify the presence of Leptospira sp or its DNA in genital tract of mares with reproductive problems. A total of 38 mares with reproductive problems were studied. All the mares were sampled for blood (for serology), urine (for culturing and qPCR), vaginal fluid-VF and endometrial biopsy-EB (for culturing, qPCR and indirect immunofluorescence). PCRs products were sequenced for secY gene. Seventeen (44.7%) serum samples were reactive, predominantly against serogroups Australis (76.4%) and Pomona (23.6%). No positive culture was obtained, but DNA was detected by qPCR on urine samples (26.3%), VF (44.7%) and EB (18.4%) collected 2 months or longer following diagnosis of early fetal death and endometritis. Leptospira cell aggregations were visible by indirect immunofluorescence on 57.1% (4/7) EBs and 17.6% (3/17) VFs. A total of 18 amplicons showed interpretable sequences. Out of those 18 amplicons, 15 presented 100% of identity with the species L. interrogans (sv Bratislava and Pomona), while three were L. borgpertersenii. This study suggests the presence of leptospires in the uterus of mares with reproductive problems. Moreover, serology was shown not to be indicated for the diagnosis of presumptive Leptospira infection in early gestation. The most common agent of the genital infection in those mares was L. interrogans, most probably sg Australis.


      PubDate: 2015-08-07T20:23:24Z
       
  • A retrospective study on equine herpesvirus type-1 associated
           myeloencephalopathy in France (2008–2011)
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Gaby van Galen, Agnes Leblond, Pierre Tritz, Ludovic Martinelle, Stéphane Pronost, Claude Saegerman
      Diagnosis of equine herpesvirus-1 associated myeloencephalopathy (EHM) can be troublesome, but early recognition and knowledge of risk factors are essential for prevention and control. The objectives for this study are to (1) describe EHM in France, (2) improve clinical recognition, (3) identify risk factors. Through epidemiosurveillance of acute neurological cases (all considered to be potentially infectious cases) in France (2008–2011), 26 EHM cases were identified and 29 EHM negative control cases. EHM cases were described and compared to controls with univariate, multivariate and classification and regression tree analysis. EHM cases had a 46% fatality rate and were frequently isolated cases. Most showed ataxia, paresis and a cauda equina syndrome, yet presence of other neurological signs was variable. Statistical analysis identified the following variables to be significantly associated to EHM compared to controls: introduction of a new horse to the herd, cauda equina syndrome, larger herd size, saddle horses and month of occurrence. The presence of many isolated cases, and less typical and variable clinical presentations emphasize the difficulty in diagnosing EHM. Nevertheless, history and clinical examination of acute neurological cases can be valuable in recognizing EHM early as well in order to select those cases that need further laboratory testing and infection control measures. Moreover, with a different study format and geographic location, risk factors were found to be similar to previous studies, therefore strengthening their significance to the spread of EHM.


      PubDate: 2015-08-07T20:23:24Z
       
  • Molecular detection of novel Anaplasmataceae closely related to Anaplasma
           platys and Ehrlichia canis in the dromedary camel (Camelus dromedarius)
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Armanda D.S. Bastos, Osama B. Mohammed, Nigel C. Bennett, Charalambos Petevinos, Abdulaziz N. Alagaili
      Serological surveys have confirmed Anaplasma marginale and Anaplasma phagocytophilum infections in dromedary camels, but molecular surveys and genetic characterisation of camel-associated Anaplasma species are lacking. In this study, we detected tick-borne Anaplasmataceae in 30 of 100 (30%) healthy dromedary camels screened using a combined 16S rRNA–groEL PCR-sequencing approach. Nucleotide sequencing confirmed Anaplasmataceae genome presence in 28 of the 33 16S rRNA PCR-positive samples, with two additional positive samples, for which 16S rRNA sequence data were ambiguous, being identified by groEL gene characterisation. Phylogenetic analyses of a 1289nt segment of the 16S rRNA gene confirmed the presence of a unique Ehrlichia lineage and a discrete Anaplasma lineage, comprising three variants, occurring at an overall prevalence of 4% and 26%, respectively. Genetic characterisation of an aligned 559nt groEL gene region revealed the camel-associated Anaplasma and Ehrlichia lineages to be novel and most closely related to Anaplasma platys and Ehrlichia canis. Based on the confirmed monophyly, minimum pairwise genetic distances between each novel lineage and its closest sister taxon, and the inability to isolate the bacteria, we propose that Candidatus status be assigned to each. This first genetic characterisation of Anaplasmataceae from naturally infected, asymptomatic dromedary camels in Saudi Arabia confirms the presence of two novel lineages that are phylogenetically linked to two pathogenic canid species of increasing zoonotic concern.


      PubDate: 2015-08-07T20:23:24Z
       
  • PCR-based retrospective evaluation of diagnostic samples for emergence of
           porcine deltacoronavirus in US swine
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Avanti Sinha, Phillip Gauger, Jianqiang Zhang, Kyoung-Jin Yoon, Karen Harmon
      Porcine deltacoronavirus (PDCoV) was first identified in Hong Kong in a regional surveillance study for Coronaviruses in 2012 and was detected for the first time in United States (US) swine in February 2014. However, it remains unknown if PDCoV had been introduced into the US prior to that time period. In the present study, 1734 clinical samples (903 cases) submitted to the Iowa State University Veterinary Diagnostic Laboratory (ISU VDL) for enteric disease diagnosis between October 2012 and December 2013 were tested retrospectively for PDCoV using a virus-specific real-time reverse transcription (RT) PCR targeting conserved region of the membrane gene. PDCoV genome was first detected in a fecal sample collected on August 19th 2013 from Minnesota. Subsequently, PDCoV was observed in samples collected on August 20th and August 27th from Iowa and on August 29th from Illinois. Therefore, with available samples submitted to the ISU VDL, it can be inferred that PDCoV has been present in US swine at least since August 2013.


      PubDate: 2015-08-07T20:23:24Z
       
  • Identification of amino acid changes in the envelope glycoproteins of
           bovine viral diarrhea viruses isolated from alpaca that may be involved in
           host adaptation
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): John D. Neill, Edward J. Dubovi, Julia F. Ridpath
      Bovine viral diarrhea viruses (BVDV) are most commonly associated with infections of cattle. However, BVDV are often isolated from closely related ruminants with a number of BVDV-1b viruses being isolated from alpacas that were both acutely and persistently infected. The complete nucleotide sequence of the open reading frame of eleven alpaca-adapted BVDV isolates and the region encoding the envelope glycoproteins of an additional three isolates were determined. With the exception of one, all alpaca isolates were >99.2% similar at the nucleotide level. The Hercules isolate was more divergent, with 95.7% sequence identity to the other viruses. Sequence similarity of the 14 viruses indicated they were isolates of a single BVDV strain that had adapted to and were circulating through alpaca herds. Hercules was a more distantly related strain that has been isolated only once in Canada and represented a separate adaptation event that possessed the same adaptive changes. Comparison of amino acid sequences of alpaca and bovine-derived BVDV strains revealed three regions with amino acid sequences unique to all alpaca isolates. The first contained two small in-frame deletions near the N-terminus of the E2 glycoprotein. The second was found near the C-terminus of the E2 protein where four altered amino acids were located within a 30 amino acid domain that participates in E2 homodimerization. The third region contained three variable amino acids in the C-terminus of the Erns within the amphipathic helix membrane anchor. These changes were found in the polar side of the amphipathic helix and resulted in an increased charge within the polar face. Titration of bovine and alpaca viruses in both bovine and alpaca cells indicated that with increased charge in the amphipathic helix, the ability to infect alpaca cells also increased.


      PubDate: 2015-08-07T20:23:24Z
       
  • Comparison of two genetically distant type 2 porcine reproductive and
           respiratory syndrome virus (PRRSV) modified live vaccines against
           Vietnamese highly pathogenic PRRSV
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Duy Tien Do, Changhoon Park, Kyuhyung Choi, Jiwoon Jeong, Toan Tat Nguyen, Khang Duong Nguyen, Dai Tan Vo, Chanhee Chae
      Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) known as pig high fever disease was first reported in China and has spread rapidly in neighboring southeastern Asian countries. The objective of this study was to evaluate the efficacy of a new type 2 PRRSV modified live vaccine (vaccine A) against a challenge with a HP-PRRSV and to compare the efficacy of two genetically distant type 2 PRRSV modified vaccines (vaccine A for lineage 8 and vaccine B for lineage 5) against HP-PRRSV (lineage 8) challenge. Pigs were divided into 4 groups (n =12/group); vaccinated challenged (2 groups), unvaccinated challenged, and unvaccinated unchallenged groups. Regardless of vaccines, vaccinated challenged pigs showed significantly lower (P <0.05) mean rectal temperatures and respiratory scores, levels of HP-PRRSV viremia, and lung lesions and HP-PRRSV antigens within lung lesions compared to unvaccinated challenged pigs. Vaccinated challenged pigs had significantly higher (P <0.05) numbers of interferon-γ secreting cells (IFN-γ-SC) compared to unvaccinated challenged pigs. Significant differences were also found when comparing two type 2 PRRSV vaccines after HP-PRRSV challenge. The use of type 2 PRRSV vaccine A was able to significantly reduce fever when compared to type 2 PRRSV vaccine B in vaccinated challenged pigs. Vaccination of pigs with vaccine A reduced viral loads in their blood and induced higher numbers of HP-PRRSV-specific IFN-γ-SC than vaccination of pigs with vaccine B. This study demonstrates partial protection of two genetically distant type 2 PRRSV vaccines against HP-PRRSV challenge in growing pigs.


      PubDate: 2015-08-07T20:23:24Z
       
  • Evaluation of BHV-1 antibody titer in a cattle herd against different
           BHV-1 strains
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Megan Lee, Aimee Reed, Charles Estill, Satoko Izume, Jing Dong, Ling Jin
      Although modified-live multivalent vaccines, such as PregGuard GOLD and Bovi-Shield Gold, have been used routinely in both beef and dairy cattle in the US, abortion and respiratory diseases still occasionally occur following vaccination. To determine whether the antibody induced by the multivalent vaccine can recognize BHV-1 isolates from aborted animals, BHV-1 antibody titer was evaluated with two isolates from abortion cases and two vaccine BHV-1 viruses. Cattle serum was collected from a dairy herd that was vaccinated annually with Bovi-Shield Gold 5 vaccine. Among the 28 cattle tested, no statistical significant difference in serum neutralization titer was observed when test virus was either vaccine virus or clinical isolates. It suggests that the BHV-1 antibody from the vaccinated cattle can recognize both the vaccine virus and clinical isolates. However, it is noticed that cows at 5 years old or older had a significantly lower BHV-1 antibody titer on average than the average of SN titer in 3 year-old cows. Similarly, cows at 5 years or older had a significantly lower BVDV antibody titer than cows at about 2 years of age. In addition, cattle vaccinated within 0–2 months had a significantly higher BHV-1 titer than those that received vaccination 6 months or greater prior to titer measurement. In contrast, cattle that received a vaccination 6 months prior had a significantly higher anti-BVDV antibody titer than those vaccinated within 1–2 months. The BVDV antibody titers remained relatively unchanged between 6 months and 1 year post-vaccination. Our study suggests little antigenic variation exists between BHV-1 disease isolates and BHV-1 of the multivalent vaccines. In addition, BHV-1 antibody titer is relatively lower at 6 months post vaccination in those tested animals. However, the BVDV antibody titer remained relatively high after 6 months from time of vaccination.
      Graphical abstract image

      PubDate: 2015-08-07T20:23:24Z
       
  • Genetic and serological surveillance for non-primate hepacivirus in horses
           in Japan
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Aya Matsuu, Seiji Hobo, Kunihide Ando, Takashi Sanekata, Fumio Sato, Yoshiro Endo, Tomohiko Amaya, Tomohiro Osaki, Masayuki Horie, Tatsunori Masatani, Makoto Ozawa, Kyoko Tsukiyama-Kohara
      Non-primate hepacivirus (NPHV) is a recently discovered homolog of the hepatitis C virus in horses. The frequency and distribution of NPHV infections among horses in Japan is unknown. In this study, serum samples from 453 horses across Japan were screened for NPHV RNA using real-time RT-PCR and anti-nonstructural 3 protein (NS3) antibodies using the Gaussia luciferase immunoprecipitation system assay. In order to monitor the course of NPHV infection in horses, we examined 31 stored samples (9 adult horses and 22 young horses) obtained one year ago and compared the results to the recent data. Stored sera from 7 mare–foal pairs were also examined. The NS3 region sequences of 14 NPHV strains from NPHV RNA positive serum samples were determined and analyzed phylogenically. Of the 453 serum samples tested, 33.55% were positive for anti-NS3 antibody and 13.68% were positive for NPHV RNA. We found a higher rate of NPHV RNA detection in serum obtained from young horses (1–2 years of age) than that of adults, in two geographically distinct areas. We observed higher variation in the course of infection over one year in young horses than in adult horses. The foals were infected with NPHV after the weaning period. Phylogenic analysis revealed that while NPHV NS3 genes isolated in Japan clustered with sequences previously classified as NPHV, but the genetic diversity of the Japanese NPHV strains we detected was not correlated with their geographic origin. In conclusion, Japanese horses exhibit a high prevalence of NPHV. Young age appears to be a risk factor for such viral infection in Japan, although the infectious route was not determined.


      PubDate: 2015-08-07T20:23:24Z
       
  • Effects of disinfection on the molecular detection of porcine epidemic
           diarrhea virus
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Andrew S. Bowman, Jacqueline M. Nolting, Sarah W. Nelson, Nola Bliss, Jason W. Stull, Qiuhong Wang, Christopher Premanandan
      Routine detection of porcine epidemic diarrhea virus (PEDV) is currently limited to RT-PCR but this test cannot distinguish between viable and inactivated virus. We evaluated the capability of disinfectants to both inactivate PEDV and sufficiently damage viral RNA beyond RT-PCR detection. Five classes of disinfectants (phenol, quaternary ammonium compound, sodium hypochlorite, oxidizing agent, and quaternary ammonium/glutaraldehyde combination) were evaluated in vitro at varying concentrations, both in the presence and absence of swine feces, and at three different temperatures. No infectious PEDV was recovered after treatment with evaluated disinfectants. Additionally, all tested disinfectants except for 0.17% sodium hypochlorite dramatically reduced qRT-PCR values. However, no disinfectants eliminated RT-PCR detection of PEDV across all replicates; although, 0.52%, 1.03% and 2.06% solutions of sodium hypochlorite and 0.5% oxidizing agent did intermittently produce RT-PCR negatives. To simulate field conditions in a second aim, PEDV was applied to pitted aluminum coupons, which were then treated with either 2.06% sodium hypochlorite or 0.5% oxidizing agent. Post-treatment surface swabs of the coupons tested RT-PCR positive but were not infectious to cultured cells or naïve pigs. Ultimately, viable PEDV was not detected following application of each of the tested disinfectants, however in most cases RT-PCR detection of viral RNA remained. RT-PCR detection of PEDV is likely even after disinfection with many commercially available disinfectants.


      PubDate: 2015-08-07T20:23:24Z
       
  • Cholesterol-rich lipid rafts play an important role in the Cyprinid
           herpesvirus 3 replication cycle
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Graham Brogden, Mikołaj Adamek, Marcus J. Proepsting, Reiner Ulrich, Hassan Y. Naim, Dieter Steinhagen
      The Cyprinus herpesvirus 3 (CyHV-3) is a member of the new Alloherpesviridae virus family in the Herpesvirales order. CyHV-3 has been implicated in a large number of disease outbreaks in carp populations causing up to 100% mortality. The aim of this study was to investigate the requirement of cholesterol-rich lipid rafts in CyHV-3 entry and replication in carp cells. Plasma membrane cholesterol was depleted from common carp brain (CCB) cells with methyl-β-cyclodextrin (MβCD). Treated and non-treated cells were infected with CyHV-3 and virus binding and infection parameters were assessed using RT-qPCR, immunocytochemistry and virus titration. The effect of cholesterol reduction severely stunted virus entry in vitro, however after cholesterol replenishment virus entry and subsequent replication rates were similar to the control infection. Furthermore, cholesterol depletion did not significantly influence virus binding and the subsequent post-entry replication stage, however had an impact on virus egress. Comparative analysis of the lipid compositions of CyHV-3 and CCB membrane fractions revealed strong similarities between the lipid composition of the CyHV-3 and CCB lipid rafts. The results presented here show that cholesterol-rich lipid rafts are important for the CyHV-3 replication cycle especially during entry and egress.


      PubDate: 2015-08-07T20:23:24Z
       
  • Isolation and characterization of a novel Rhabdovirus from a wild boar
           (Sus scrofa) in Japan
    • Abstract: Publication date: 30 September 2015
      Source:Veterinary Microbiology, Volume 179, Issues 3–4
      Author(s): Kouji Sakai, Katsuro Hagiwara, Tsutomu Omatsu, Chinami Hamasaki, Ryusei Kuwata, Hiroshi Shimoda, Kazuo Suzuki, Daiji Endoh, Noriyo Nagata, Makoto Nagai, Yukie Katayama, Mami Oba, Ichiro Kurane, Masayuki Saijo, Shigeru Morikawa, Tetsuya Mizutani, Ken Maeda
      A novel rhabdovirus was isolated from the serum of a healthy Japanese wild boar (Sus scrofa leucomystax) and identified using the rapid determination system for viral nucleic acid sequences (RDV), next-generation sequencing, and electron microscopy. The virus was tentatively named wild boar rhabdovirus 1 (WBRV1). Phylogenetic analysis of the entire genome sequence indicated that WBRV1 is closely related to Tupaia rhabdovirus (TRV), which was isolated from cultured cells of hepatocellular carcinoma tissue of tree shrew. TRV has not been assigned to any genus of Rhabdoviridae till date. Analysis of the L gene indicated that WBRV1 belongs to the genus Vesiculovirus. These observations suggest that both TRV and WBRV1 belong to a new genus of Rhabdoviridae. Next-generation genome sequencing of WBRV1 revealed 5 open reading frames of 1329, 765, 627, 1629, and 6336 bases in length. The WBRV1 gene sequences are similar to those of other rhabdoviruses. Epizootiological analysis of a population of wild boars in Wakayama prefecture in Japan indicated that 6.5% were positive for the WBRV1 gene and 52% were positive for WBRV1-neutralizing antibodies. Furthermore, such viral neutralizing antibodies were found in domestic pigs in another prefecture. WBRV1 was inoculated intranasally and intraperitoneally into SCID and BALB/c mice and viral RNA was detected in SCID mice, suggesting that WBRV1 can replicate in immunocompromised mice. These results indicate this novel virus is endemic in wild animals and livestock in Japan.


      PubDate: 2015-08-07T20:23:24Z
       
  • Corrigendum to ‘Characterisation of a mobilisable plasmid conferring
           florfenicol and chloramphenicol resistance in Actinobacillus
           pleuropneumoniae’ [Veterinary Microbiology 178 (2015) 279–282]
           
    • Abstract: Publication date: Available online 22 July 2015
      Source:Veterinary Microbiology
      Author(s): Janine T. Bossé, Yanwen Li, Tom G. Atherton, Stephanie Walker, Susanna M. Williamson, Jon Rogers, Roy R. Chaudhuri, Lucy A. Weinert, Matthew T.G. Holden, Duncan J. Maskell, Alexander W. Tucker, Brendan W. Wren, Andrew N. Rycroft, Paul R. Langford



      PubDate: 2015-07-23T09:21:15Z
       
  • Virulence, persistence and dissemination of Mycoplasma bovis
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Sibylle Bürki, Joachim Frey, Paola Pilo
      Bovine mycoplasmosis due to Mycoplasma bovis causes several important bovine diseases such as pneumonia, mastitis, arthritis, otitis, genital disorders or keratoconjunctivitis. Variable surface lipoproteins, adhesion, invasion of host cells, modulation of the host immune system, biofilm formation and the release of secondary metabolites like hydrogen peroxide, as well as synergistic infections with other bacterial or viral pathogens are among the more significantly studied characteristics of the bacterium. The aim of this review is to summarize the current knowledge regarding the virulence of M. bovis and additionally, factors contributing to the dissemination and persistence of this pathogen in the bovine host will be discussed.


      PubDate: 2015-07-19T08:23:33Z
       
  • Mucosally Administered Lactobacillus Surface-Displayed Influenza Antigens
           (sM2 and HA2) with Cholera Toxin Subunit A1 (CTA1) Induce Broadly
           Protective Immune Responses against Divergent Influenza Subtypes
    • Abstract: Publication date: Available online 17 July 2015
      Source:Veterinary Microbiology
      Author(s): Rui Li, Mohammed Y.E. Chowdhury, Jae-Hoon Kim, Tae-Hwan Kim, Prabuddha Pathinayake, Wan-Seo Koo, Min-Eun Park, Ji-Eun Yoon, Jong-Bok Roh, Seung-Pyo Hong, Moon-Hee Sung, Jong-Soo Lee, Chul-Joong Kim
      The development of a universal influenza vaccine that provides broad cross protection against existing and unforeseen influenza viruses is a critical challenge. In this study, we constructed and expressed conserved sM2 and HA2 influenza antigens with cholera toxin subunit A1 (CTA1) on the surface of Lactobacillus casei (pgsA-CTA1sM2HA2/L. casei). Oral and nasal administrations of recombinant L. casei into mice resulted in high levels of serum immunoglobulin G (IgG) and their isotypes (IgG1 & IgG2a) as well as mucosal IgA. The mucosal administration of pgsA-CTA1sM2HA2/L. casei may also significantly increase the levels of sM2- or HA2-specific cell-mediated immunity because increased release of both IFN-γ and IL-4 was observed. The recombinant pgsA-CTA1sM2HA2/L. casei provided better protection of BALB/c mice against 10 times the 50% mouse lethal doses (MLD50) of homologous A/EM/Korea/W149/06(H5N1) or A/Aquatic bird /Korea/W81/2005 (H5N2) and heterologous A/Puerto Rico/8/34(H1N1), or A/Chicken/Korea/116/2004(H9N2) or A/Philippines/2/08(H3N2) viruses, compared with L. casei harboring sM2HA2 and also the protection was maintained up to seven months after administration. These results indicate that recombinant L. casei expressing the highly conserved sM2, HA2 of influenza and CTA1 as a mucosal adjuvant could be a potential mucosal vaccine candidate or tool to protect against divergent influenza viruses for human and animal.


      PubDate: 2015-07-19T08:23:33Z
       
  • Characterisation of the Equine adenovirus 2 genome
    • Abstract: Publication date: Available online 18 July 2015
      Source:Veterinary Microbiology
      Author(s): Carla Giles, Thiru Vanniasinkam, Mary Barton, Timothy J. Mahony
      Equine adenovirus 2 (EAdV-2) is one of two serotypes of adenoviruses known to infect equines. Initial studies did not associate EAdV-2 infections with any specific clinical syndromes, although more recent evidence suggests that EAdV-2 may be associated with clinical and subclinical gastrointestinal infections of foals and adults respectively. In contrast, Equine adenovirus 1 is well recognised as a pathogen associated with upper respiratory tract infections of horses. In this study the complete genome sequence of EAdV-2 is reported. As expected, genes common to the adenoviruses were identified. Phylogenetic reconstructions using selected EAdV-2 genes confirmed the classification of this virus within the Mastadenovirus genus, and supported the hypothesis that EAdV-2 and EAdV-1 have evolved from separate lineages within the adenoviruses. One spliced open reading frame was identified that encoded for a polypeptide with high similarity to the pIX and E1b_55K adenovirus homologues and was designated pIX_E1b_55K. In addition to this fused version of E1b_55K, a separate E1b_55K encoding gene was also identified. These polypeptides do not appear to have evolved from a gene duplication event as the fused and unfused E1b_55K were most similar to E1b_55K homologues from the Atadenovirus and Mastadenovirus genera respectively. The results of this study suggest that EAdV-2 has an unusual evolutionary history that warrants further investigation.


      PubDate: 2015-07-19T08:23:33Z
       
  • Activation of persistent Streptococcus equi subspecies zooepidemicus in
           mares with subclinical endometritis
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): M.R. Petersen, B. Skive, M. Christoffersen, K. Lu, J.M. Nielsen, M.H.T. Troedsson, A.M. Bojesen
      Endometritis in horses caused by Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) may be underdiagnosed due to traditional diagnostic methods lacking sensitivity and specificity. We serendipitously identified a bacterial growth medium (bActivate) that appeared capable of inducing growth of dormant S. zooepidemicus, which subsequently allowed detection by standard diagnostics. To assess the effect of bActivate we compared its ability to activate dormant S. zooepidemicus in a group of potentially infected subfertile mares with phosphate-buffered saline (PBS). All mares had to test negative for S. zooepidemicus on a low-volume uterine lavage, be negative on endometrial cytology and without clinical signs of endometritis to be included in the investigation. The mares were instilled with bActivate or PBS in the uterus. Growth of S. zooepidemicus was induced by bActivate in 64% (16/25) and PBS in 8% (1/12) of the mares, respectively (p <0.002). In vitro studies supported that some strains of S. zooepidemicus were able to form persister cells tolerating 32-times of the minimal inhibitory concentration of penicillin compared to normal growing cells. Persister cells had not acquired penicillin resistance, but seemed to tolerate the antimicrobial due to dormancy. This is, to our knowledge, the first description of controlled growth induction of dormant bacteria from a subclinical infection. Moreover we demonstrated how endometritis can origin from a reservoir of dormant bacteria residing within the endometrium, and not only as an ascending infection. Further studies should aim at determining the prevalence of dormant S. zooepidemicus, impact of activation on diagnostic and treatment efficacy, uterine health and mare fertility.


      PubDate: 2015-07-19T08:23:33Z
       
  • Phenotypic features and phylogenetic background of extraintestinal
           hemolytic Escherichia coli responsible of mortality in puppies
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Sara Turchetto, Martina Ustulin, Carlo Vittorio Citterio, Claudia Zanardello, Marta Vascellari, Denis Vio, Gabriella Conedera, Nicola Maria Ferro Milone, Monia Cocchi
      A 10-day-old litter of five puppies of Bracco Italiano dog breed showed weakness and diarrhea and, 2 days later, four of them died. At the same time, the bitch showed high hyperthermia (40°C) and endometritis. The necropsy of a puppy revealed a severe lobar pneumonia accompanied with a bilateral nephrosis. No gross lesions were detected in other organs. Histopathology of the lung revealed severe multifocal fibrino-suppurative necrotizing bronchiolar-alveolitis associated with rod-shaped bacterial aggregates and diffuse interstitial lymphocytic infiltration. The kidney showed severe multifocal necrosis of the tubular epithelium and diffuse severe congestion of the parenchyma. A pure culture of hemolytic Escherichia coli carrying the Cnf-1 gene was identified, from both the puppy organs and bitch's milk. Moreover, phylo-typing assigned them to the phylogroup B2. Two weeks later, fecal samples from the bitch and the survived puppy were collected for a second microbiological analysis, identifying two hemolytic E. coli strains, Cnf positive and Cdt negative and Cnf and Cdt negative, respectively. Some E. coli pathogenic strains may cause enteric or extraintestinal disease. In dogs and cats, strains of extraintestinal pathogenic E. coli (ExPEC) produce specific virulent factors such as hemolysis and cytotoxin necrotizing factors (Cnf). In this episode, we hypothesize that the bitch's milk could be the main source of ExPEC infection causing high puppies mortality. The role of the bitch as a carrier could not be excluded: stressful conditions, such as pregnancy and delivery, would change the host–pathogen dynamics possibly increasing the release of the infectious burden.


      PubDate: 2015-07-19T08:23:33Z
       
  • Molecular characterization of Salmonella enterica isolates associated with
           starling–livestock interactions
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): James C. Carlson, Doreene R. Hyatt, Kevin Bentler, Anna M. Mangan, Michael Russell, Antoinette J. Piaggio, George M. Linz
      Bird–livestock interactions have been implicated as potential sources for bacteria within concentrated animal feeding operations (CAFO). In this study we characterized XbaI-digested genomic DNA from Salmonella enterica using pulsed-field gel electrophoresis (PFGE). The PFGE analysis was conducted using 182 S. enterica isolates collected from a single CAFO between 2009 and 2012. Samples collected in 2012 were subjected to antimicrobial susceptibility testing. The analysis was limited to S. enterica serotypes, with at least 10 isolates, known to occur in both European starlings (Sturnus vulgaris) and cattle (Bos taurus) within this CAFO. A total of five different serotypes were screened; S. Anatum, S. Kentucky, S. Meleagridis, S. Montevideo, S. Muenchen. These samples were recovered from five different sample types; starling gastrointestinal tracts (GI), starling external wash, cattle feces, cattle feed and cattle water troughs. Indistinguishable S. enterica PFGE profiles were recovered from isolates originating in all sample types. Antimicrobial resistance (AMR) was also associated with indistinguishable S. enterica isolates recovered from all samples types. These data suggests that AMR S. enterica is transmitted between cattle and starlings and that shared feed sources are likely contributing to infections within both species. Moreover we isolated indistinguishable PFGE profiles across all years of data collection, suggesting long-term environmental persistence may be mediated by starling visits to CAFO.


      PubDate: 2015-07-19T08:23:33Z
       
  • IFAT and ELISA phase I/phase II as tools for the identification of Q fever
           chronic milk shedders in cattle
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Laura Lucchese, Katia Capello, Antonio Barberio, Federica Zuliani, Arjan Stegeman, Letizia Ceglie, Eulalia Guerrini, Stefano Marangon, Alda Natale
      Q fever is a widespread zoonotic disease caused by Coxiella burnetii. In cattle the bacterial shedding can persist without symptoms for several months and the shedders identification is a critical issue in the control of the infection at herd level. Following the example of the human protocols for the assessment of Q fever infection status, the aim of this study was the evaluation of the antibody response dynamics to phase I and phase II antigens in C. burnetii shedder dairy cows by means of a phase-specific serology, to verify the suitability of the investigated tools in recognising milk shedders. A total of 99 cows were monitored during time and classified on the basis of serological and PCR results in five groups identifying different shedding patterns. The 297 sera collected in three sampling times were tested by means of ELISA IgG for differential phase I and phase II antibodies detection, while a selection of 107 sera were tested by means of phase specific IgM and IgG IFAT. Both ELISA IgG and IFAT IgG highlighted a low reactivity in non-shedder seropositive animals compared to chronic milk shedder animals. ELISA IgG seemed to perform better than IFAT IgG–IgM, showing significant serological differences among groups that allowed recognising specific serological group patterns, in particular for chronic and occasional milk shedders. These results supported the hypothesis that an animal classification based on phase patterns is reasonable, although it needs to be further investigated.


      PubDate: 2015-07-19T08:23:33Z
       
  • Characterisation of Dichelobacter nodosus and detection of Fusobacterium
           necrophorum and Treponema spp. in sheep with different clinical
           manifestations of footrot
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Sara Frosth, Ulrika König, Ann-Kristin Nyman, Märit Pringle, Anna Aspán
      The aim of this study was to determine the proportion of Dichelobacter nodosus, Fusobacterium necrophorum and Treponema spp. in sheep with different clinical manifestations of footrot compared to healthy sheep both at flock and individual level. The second aim was to characterise D. nodosus with respect to virulence, presence of intA gene and the serogroups. Swab samples (n =1000) from footrot-affected (n =10) and healthy flocks (n =10) were analysed for the presence of D. nodosus, F. necrophorum and Treponema spp. by real-time PCR and culturing (D. nodosus only). Dichelobacter nodosus isolates (n =78) and positive swabs (n =474) were analysed by real-time PCR for the aprV2/B2 and the intA genes and by PCR for the fimA gene (isolates only). D. nodosus was more commonly found in flocks affected with footrot than in clinically healthy flocks. A significant association was found between feet with severe footrot lesions and the aprV2 gene and between feet with moderate or no lesions and the aprB2 gene, respectively. F. necrophorum was more commonly found in flocks with footrot lesions than in flocks without lesions. No significant association was found between sheep flocks affected with footrot and findings of Treponema spp. or the intA gene. Benign D. nodosus of six different serogroups was detected in twelve flocks and virulent D. nodosus of serogroup G in one. In conclusion, D. nodosus and F. necrophorum were more commonly found in feet with footrot than in healthy feet. The majority of D. nodosus detected was benign, while virulent D. nodosus was only detected in a single flock.


      PubDate: 2015-07-19T08:23:33Z
       
  • A naturally occurring prfA truncation in a Listeria monocytogenes field
           strain contributes to reduced replication and cell-to-cell spread
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Sebastian Rupp, Lisandra Aguilar-Bultet, Vidhya Jagannathan, Claudia Guldimann, Cord Drögemüller, Christiane Pfarrer, Beatriz Vidondo, Torsten Seuberlich, Joachim Frey, Anna Oevermann
      Listeria (L.) monocytogenes is an environmental bacterium that may become an intracellular pathogen upon ingestion to cause gastroenteritis, septicaemia, abortions, and/or fatal infections of the central nervous system. We here describe a L. monocytogenes field strain (JF5171) isolated from a bovine placenta in the context of abortion, which exhibited attenuation in bovine brain-slice cultures. The whole genome of strain JF5171 was sequenced, and the invasion, replication, and intercellular spread of JF5171 were further analyzed by quantification of colony forming units and immunofluorescence studies. Phospholipase and hemolysis activity of JF5171 were also quantified along with transcription levels of actA, hly and prfA. The data obtained were compared to those of the widely used L. monocytogenes reference strain, EGD-e. JF5171 exhibited reduced replication and lower levels of phospholipase and hemolysis activity. Invasion and cell-to-cell spread was strongly decreased compared to EGD-e, and actin polymerization was absent. A frame shift deletion was identified in the JF5171 coding region of the major regulator for virulence, prfA. This resulted in a truncated C-terminus sequence (WEN* vs. WGKLN*). In addition, a point mutation resulted in a lysine to arginine substitution at amino acid position 197. Complementation with prfA from EGD-e and with (EGD-e) prfA-K197N increased the replication and spread efficiency of JF5171. In contrast, complementation with the truncated version of prfA had no effect. Taken together, these results suggest that the truncated C-terminus of prfA considerably contributes to the strongly attenuated phenotype observed in vitro.


      PubDate: 2015-07-19T08:23:33Z
       
  • Mechanisms of antimicrobial resistant Salmonella enterica transmission
           associated with starling–livestock interactions
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): James C. Carlson, Doreene R. Hyatt, Jeremy W. Ellis, David R. Pipkin, Anna M. Mangan, Michael Russell, Denise S. Bolte, Richard M. Engeman, Thomas J. DeLiberto, George M. Linz
      Bird–livestock interactions have been implicated as potential sources for bacteria within concentrated animal feeding operations (CAFO). European starlings (Sturnus vulgaris) in particular are known to contaminate cattle feed and water with Salmonella enterica through their fecal waste. We propose that fecal waste is not the only mechanisms through which starlings introduce S. enterica to CAFO. The goal of this study was to assess if starlings can mechanically move S. enterica. We define mechanical movement as the transportation of media containing S. enterica, on the exterior of starlings within CAFO. We collected 100 starlings and obtained external wash and gastrointestinal tract (GI) samples. We also collected 100 samples from animal pens. Within each pen we collected one cattle fecal, feed, and water trough sample. Isolates from all S. enterica positive samples were subjected to antimicrobial susceptibility testing. All sample types, including 17% of external starling wash samples, contained S. enterica. All sample types had at least one antimicrobial resistant (AMR) isolate and starling GI samples harbored multidrug resistant S. enterica. The serotypes isolated from the starling external wash samples were all found in the farm environment and 11.8% (2/17) of isolates from positive starling external wash samples were resistant to at least one class of antibiotics. This study provides evidence of a potential mechanism of wildlife introduced microbial contamination in CAFO. Mechanical movement of microbiological hazards, by starlings, should be considered a potential source of bacteria that is of concern to veterinary, environmental and public health.


      PubDate: 2015-07-19T08:23:33Z
       
  • Outbreak investigation identifies a single Listeria monocytogenes strain
           in sheep with different clinical manifestations, soil and water
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): M. Dreyer, A. Thomann, S. Böttcher, J. Frey, A. Oevermann
      Listeria (L.) monocytogenes causes orally acquired infections and is of major importance in ruminants. Little is known about L. monocytogenes transmission between farm environment and ruminants. In order to determine potential sources of infection, we investigated the distribution of L. monocytogenes genetic subtypes in a sheep farm during a listeriosis outbreak by applying four subtyping methods (MALDI-TOF-MS, MLST, MLVA and PFGE). L. monocytogenes was isolated from a lamb with septicemia and from the brainstem of three sheep with encephalitis. Samples from the farm environment were screened for the presence of L. monocytogenes during the listeriosis outbreak, four weeks and eight months after. L. monocytogenes was found only in soil and water tank swabs during the outbreak. Four weeks later, following thorough cleaning of the barn, as well as eight months later, L. monocytogenes was absent in environmental samples. All environmental and clinical L. monocytogenes isolates were found to be the same strain. Our results show that the outbreak involving two different clinical syndromes was caused by a single L. monocytogenes strain and that soil and water tanks were potential infection sources during this outbreak. However, silage cannot be completely ruled out as the bales fed prior to the outbreak were not available for analysis. Faeces samples were negative, suggesting that sheep did not act as amplification hosts contributing to environmental contamination. In conclusion, farm management appears to be a crucial factor for the limitation of a listeriosis outbreak.


      PubDate: 2015-07-19T08:23:33Z
       
  • The role of the environment in transmission of Dichelobacter nodosus
           between ewes and their lambs
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Mohd Muzafar, Leo A. Calvo-Bado, Laura E. Green, Edward M. Smith, Claire L. Russell, Rose Grogono-Thomas, Elizabeth M.H. Wellington
      Dichelobacter nodosus (D. nodosus) is the essential causative agent of footrot in sheep. The current study investigated when D. nodosus was detectable on newborn lambs and possible routes of transmission. Specific qPCR was used to detect and quantify the load of D. nodosus in foot swabs of lambs at birth and 5–13h post-partum, and their mothers 5–13h post-partum; and in samples of bedding, pasture, soil and faeces. D. nodosus was not detected on the feet of newborn lambs swabbed at birth, but was detected 5–13h after birth, once they had stood on bedding containing naturally occurring D. nodosus. Multiple genotypes identified by cloning and sequencing a marker gene, pgrA, and by multi locus variable number tandem repeat analysis (MLVA) of community DNA from swabs on individual feet indicated a mixed population of D. nodosus was present on the feet of both ewes and lambs. There was high variation in pgrA tandem repeat number (between 3 and 21 repeats), and multiple MLVA types. The overall similarity index between the populations on ewes and lambs was 0.45, indicating moderate overlap. Mother offspring pairs shared some alleles but not all, suggesting lambs were infected from sources(s) other than just their mother's feet. We hypothesise that D. nodosus is transferred to the feet of lambs via bedding containing naturally occurring populations of D. nodosus, probably as a result of transfer from the feet of the group of housed ewes. The results support the hypothesis that the environment plays a key role in the transmission of D. nodosus between ewes and lambs.


      PubDate: 2015-07-19T08:23:33Z
       
  • Structural characterisation of the virulence-associated protein VapG from
           the horse pathogen Rhodococcus equi
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Tebekeme Okoko, Elena V. Blagova, Jean L. Whittingham, Lynn G. Dover, Anthony J. Wilkinson
      Virulence and host range in Rhodococcus equi depends on the variable pathogenicity island of their virulence plasmids. Notable gene products are a family of small secreted virulence-associated proteins (Vaps) that are critical to intramacrophagic proliferation. Equine-adapted strains, which cause severe pyogranulomatous pneumonia in foals, produce a cell-associated VapA that is necessary for virulence, alongside five other secreted homologues. In the absence of biochemical insight, attention has turned to the structures of these proteins to develop a functional hypothesis. Recent studies have described crystal structures for VapD and a truncate of the VapA orthologue of porcine-adapted strains, VapB. Here, we crystallised the full-length VapG and determined its structure by molecular replacement. Electron density corresponding to the N-terminal domain was not visible suggesting that it is disordered. The protein core adopted a compact elliptical, anti-parallel β-barrel fold with β1–β2–β3–β8–β5–β6–β7–β4 topology decorated by a single peripheral α-helix unique to this family. The high glycine content of the protein allows close packing of secondary structural elements. Topologically, the surface has no indentations that indicate a nexus for molecular interactions. The distribution of polar and apolar groups on the surface of VapG is markedly uneven. One-third of the surface is dominated by exposed apolar side-chains, with no ionisable and only four polar side-chains exposed, giving rise to an expansive flat hydrophobic surface. Other surface regions are more polar, especially on or near the α-helix and a belt around the centre of the β-barrel. Possible functional significance of these recent structures is discussed.


      PubDate: 2015-07-19T08:23:33Z
       
  • A two-component regulatory system modulates twitching motility in
           Dichelobacter nodosus
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Ruth M. Kennan, Carrie J. Lovitt, Xiaoyan Han, Dane Parker, Lynne Turnbull, Cynthia B. Whitchurch, Julian I. Rood
      Dichelobacter nodosus is the essential causative agent of footrot in sheep and type IV fimbriae-mediated twitching motility has been shown to be essential for virulence. We have identified a two-component signal transduction system (TwmSR) that shows similarity to chemosensory systems from other bacteria. Insertional inactivation of the gene encoding the response regulator, TwmR, led to a twitching motility defect, with the mutant having a reduced rate of twitching motility when compared to the wild-type and a mutant complemented with the wild-type twmR gene. The reduced rate of twitching motility was not a consequence of a reduced growth rate or decreased production of surface located fimbriae, but video microscopy indicated that it appeared to result from an overall loss of twitching directionality. These results suggest that a chemotactic response to environmental factors may play an important role in the D. nodosus-mediated disease process.


      PubDate: 2015-07-19T08:23:33Z
       
  • Animal models to study the pathogenesis of human and animal Clostridium
           perfringens infections
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Francisco A. Uzal, Bruce A. McClane, Jackie K. Cheung, James Theoret, Jorge P. Garcia, Robert J. Moore, Julian I. Rood
      The most common animal models used to study Clostridium perfringens infections in humans and animals are reviewed here. The classical C. perfringens-mediated histotoxic disease of humans is clostridial myonecrosis or gas gangrene and the use of a mouse myonecrosis model coupled with genetic studies has contributed greatly to our understanding of disease pathogenesis. Similarly, the use of a chicken model has enhanced our understanding of type A-mediated necrotic enteritis in poultry and has led to the identification of NetB as the primary toxin involved in disease. C. perfringens type A food poisoning is a highly prevalent bacterial illness in the USA and elsewhere. Rabbits and mice are the species most commonly used to study the action of enterotoxin, the causative toxin. Other animal models used to study the effect of this toxin are rats, non-human primates, sheep and cattle. In rabbits and mice, CPE produces severe necrosis of the small intestinal epithelium along with fluid accumulation. C. perfringens type D infection has been studied by inoculating epsilon toxin (ETX) intravenously into mice, rats, sheep, goats and cattle, and by intraduodenal inoculation of whole cultures of this microorganism in mice, sheep, goats and cattle. Molecular Koch's postulates have been fulfilled for enterotoxigenic C. perfringens type A in rabbits and mice, for C. perfringens type A necrotic enteritis and gas gangrene in chickens and mice, respectively, for C. perfringens type C in mice, rabbits and goats, and for C. perfringens type D in mice, sheep and goats.


      PubDate: 2015-07-19T08:23:33Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2




      PubDate: 2015-07-19T08:23:33Z
       
  • Preface
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Ben Adler, Joachim Frey



      PubDate: 2015-07-19T08:23:33Z
       
  • Interplay between iron homeostasis and virulence: Fur and RyhB as major
           regulators of bacterial pathogenicity
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Gaëlle Porcheron, Charles M. Dozois
      In bacteria–host interactions, competition for iron is critical for the outcome of the infection. As a result of its redox properties, this metal is essential for the growth and proliferation of most living organisms, including pathogenic bacteria. This metal is also potentially toxic, making the precise maintenance of iron homeostasis necessary for survival. Iron acquisition and storage control is mediated in most bacteria by the global ferric uptake regulator (Fur) and iron-responsive small regulatory non-coding RNAs (RyhB in the model organism Escherichia coli). While the role of these regulators in iron homeostasis is well documented in both pathogenic and non-pathogenic bacteria, many recent studies also demonstrate that these regulators are involved in the virulence of pathogenic bacteria. By sensing iron availability in the environment, Fur and RyhB are able to regulate, either directly or indirectly via other transcriptional regulators or modulation of intracellular iron concentration, many virulence determinants of pathogenic bacteria. Iron is thus both a nutritional and regulatory element, allowing bacteria to adapt to various host environments by adjusting expression of virulence factors. In this review, we present evidences that Fur and RyhB are the major regulators of this adaptation, as they are involved in diverse functions ranging from iron homeostasis to regulation of virulence by mediating key pathogen responses such as invasion of eukaryotic cells, toxin production, motility, quorum sensing, stress resistance or biofilm formation. Therefore, Fur and RyhB play a major role in regulating an adaptative response during bacterial infections, making them important targets in the fight against pathogenic bacteria.


      PubDate: 2015-07-19T08:23:33Z
       
  • A new bovine conjunctiva model shows that Listeria monocytogenes invasion
           is associated with lysozyme resistance
    • Abstract: Publication date: 31 August 2015
      Source:Veterinary Microbiology, Volume 179, Issues 1–2
      Author(s): Jessica Warren, A. Rhys Owen, Amy Glanvill, Asher Francis, Grazieli Maboni, Rodrigo J. Nova, Wendela Wapenaar, Catherine Rees, Sabine Tötemeyer
      Listerial keratoconjunctivitis (‘silage eye’) is a wide spread problem in ruminants causing economic losses to farmers and impacts negatively on animal welfare. It results from direct entry of Listeria monocytogenes into the eye, often following consumption of contaminated silage. An isolation protocol for bovine conjunctival swabbing was developed and used to sample both infected and healthy eyes bovine eyes (n =46). L. monocytogenes was only isolated from one healthy eye sample, and suggests that this organism can be present without causing disease. To initiate a study of this disease, an infection model was developed using isolated conjunctiva explants obtained from cattle eyes post slaughter. Conjunctiva were cultured and infected for 20h with a range of L. monocytogenes isolates (n =11), including the healthy bovine eye isolate and also strains isolated from other bovine sources, such as milk or clinical infections. Two L. monocytogenes isolates (one from a healthy eye and one from a cattle abortion) were markedly less able to invade conjunctiva explants, but one of those was able to efficiently infect Caco2 cells indicating that it was fully virulent. These two isolates were also significantly more sensitive to lysozyme compared to most other isolates tested, suggesting that lysozyme resistance is an important factor when infecting bovine conjunctiva. In conclusion, we present the first bovine conjunctiva explant model for infection studies and demonstrate that clinical L. monocytogenes isolates from cases of bovine keratoconjunctivitis are able to infect these tissues.


      PubDate: 2015-07-19T08:23:33Z
       
 
 
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